1. Field of the Invention:
This invention relates in general to equipment for recovering refrigerant, and in particular to equipment for recovering large quantities of refrigerant.
2. Description of the Prior Art:
In the past, large quantities of CFC refrigerants were vented to the atmosphere when the unit utilizing the refrigerants needed to be repaired or decommissioned. Subsequently, it was learned that the refrigerants lead to depletion of the ozone layer. Now it is prohibited to vent refrigerants to atmosphere.
Recovery units currently in use normally have a compressor, evaporator and a condenser. Vapor refrigerant is drawn into the compressor, which pressurizes the vapor and forwards it to the condenser. The vapor condenses into a liquid in the condenser, and from there it passes to the storage bottle. Liquid refrigerant withdrawn from the system passes through an expansion valve which drops the pressure, causing it to vaporize. The vaporized cold refrigerant passes through an evaporator which removes heat, and from there the vapor passes to the suction side of the compressor.
While these systems work well enough for small quantities of refrigerant removal, they normally will not handle very high flow rates. Consequently in large commercial air conditioning or refrigeration units, removing the refrigerant is very time consuming. The small units are not be able to accommodate the necessary heat exchange during the evaporating and condensing steps.